Dynamo-electric machine and the like.



No. 830,025. PATENTED SEPT. 4, 1906. L. TORDA.

DYNAMO ELECTRIC MACHINE AND THE LIKE.

APPLICATION FILED JUNE 2.1905.

WITNESSES INVENTOR fiywy/y% ilzzdwzig/ Z527! \fd Br 5% W a A T TOHNEYS ject of the Emperor of Austria-Hungary, re-

UNITED sTATEs PATENT OFFICE.

DYNAMO-ELECTRIC MACHINE-AND THE LIKE..

Specification of Letters Patent.

Application filed June 2, 1905. Serial No. 263.381.

Patented Sept. 4, 1906.

T!) all whom it may concern:

Be it known that I, LUDWIG TonnA, a subsiding at Barking, in the county of Essex,

England, have invented certain new and useful Improvements in Dynamo-Electric Machines and the Like, of which the following is a s ecification, such as .will enable those skil ed in the art to-Which it appertains to make and use the same. This invention relates generally to dynamo-electric machines with commutators, and especially to continuous-current machines, and has for its principal object to improve such machines by means of auxiliary or commutating magnets.

The-invention consists, essentially, of the construction and arrangement of commutating-magnets, which, compared with existin devices of this class, offers some electricaT and constructional advantages,

Hitherto the'employment of commutating-magnets has been restricted, owing to their use involving complications of the whole machine, extra cost,- and the uncertaintyin the design of the commutatingmagnets, and forthis reason the application of special means for adjustmentas, for instance, separate resistances for the regulation of the current in the commutating-magnet winding.

With commutating-magnets constructed according to this invention the cost is reduced to a minimum and the magnets are easily adjustable without use of separate resistances. especially advantageous for high-s eed dynamos and motors, for variable-v0 tage dynamos, and for variable-speed motors for high-voltage and high-amperage machines, but also for normal ty es of machines.

The invention is ful y'disclosed in the following specification, of which the accompanying drawings form a part, in which the separate parts of my improvement are, designated by suitable reference characters in each of the views, and in which Figure 1 is a front view of a dynamo con-- structed according to my invention; Fig. 2, a section on'the line 2 2 of Fig. 1, with the armature removed; Fig.3, a vlew similar to .Fig. 2 and showing a modification; Fig. 4, a

perspective view of a detail of the construction, illustrating the mechanical connect ons between the pole-pieces of the commutatmg- "proper positions.

Its application will be found magnets and the field-magnets;-and Fig. 5, a diagrammatic view of the field and commutating windings.

In the drawings forming part of this speci- V fication I have indicated at f the yoke of an ordinary dynamic electrical machine within which are mounted a plurality of main magnets m" and commutating-magnets n, said commutating-magnets n comprising a core a.

and the usual windin b therefor, and said cores (1 are movable in oles d, formed in lugs e on the yoke f, and said cores a are held in the lugs e by means of nuts 9 or in any other suitab e manner, and secured to each of the cores a is a pole-shoe i.

The main magnets m are provided with the usual magnet-cores c and windings therefor, and also with pole-shoes j, and the main-magnet pole -shoes 1' and commutating-magnet pole-shoes t are secured together by means of bands or strips h of suitable electrical conductivity, and said strips or bands It serve also asmechanical strengtheners for the poleshoes 'L and hold the same rigidly in their In practice I prefer to shape the commutatin -magnet cores so that the pole-shoes thereo .are placed between the pole-shoes of the main magnets in order that the common plane of all the main-magnet cores and'the shoes thereof may also be the common plane of the commutating poleshoes, but not that of the commutating-magnet cores, which are placed in a plane parallel to the former plane, and I prefer to make the cores of the commutating-magnets longer than the cores of the main magnets, and because of the arrangement of the commutating-magnet cores 0, in the lugs e the air-gap between the armature and commutatingmagnet shoes is made easily adjustable. In this manner I can apply a commutatingmagnet core so formed that the length of the magnet-coil winding which affects the cost of the device will be reduced to a minimum.

For a given number of ampere-turnswhich is to generate the necessary commutating field the length of the winding, and therewith the Weight of the commutating-magnet, copper for a certain current density, will be a minimum when the mean length of a turn is as short as possible. The mean length of a turn will be the shortest when the core-section is circular inshape and when the number of ampere-turns per inch length of the core has a reasonably low value. As a rule it Will be found advantageous to make the core length of the commutating-magnets longer than that of the main magnets.

The size of the core-section of a given magnetic material is de endent on the strength of the commutating eld necessary for reversing sparklessly the current in the armaturecoils undergoing commutation. 0n the other hand, the necessary strength of the commu tating field is dependent on the so-called reactance voltage of the armature-coil under commutation. The greater the reactance voltage the stronger must be the commutating field. The size'oi -the core-section is therefore dependent upon the reactance voltage.

As is known, the reactance of a coil is greatly diminished by placing a closed circuit,

preferably oi the same shape, in close proximity to the coil. 1 therefore connect together the ole-shoes oi the commutatingmagnets, wiich are in close proximity of the armature-coilsunder oing commutation, with strips, bars, or the lilre of good electrical conductivity in order to form a closed electric circuit, and said strips or plate may be of any preferred shape to accomplish the desired result. By this simple means the reactance voltage is diminished and correspondingly the section of the coinmutatingmagnet cores and the weight or the magnet copper is reduced.

As the reactance is principally due to that portion oi the armature-coils which is embedded in the armature-slot, it is sui ficient to connect together the pole-shoes directly in the shortest possible way without following the shape of the armature-coil outside the slot. Although in case the reactance of those portions of the armature-coils which are not embedded in the slots represents propor-. tionately a considerable amount, the said bands may receive a shape concentric to the armature. ln this case it is preferable in most cases to connect the commutating pole shoes with the tips of the main pole-shoes, thus reducing considerably the length of the connections. These connections may serve at the same time to increase the rigidity of the mechanical construction of the commutating-magnet system.

in case the pole-shoes are made of laminated iron, bolts of any suitable material in close proximity to the armature surface, which at the same time are to hold together the laminations, are used asparts tr the said closed circuits.

lln order to be enabled to give a proper length to the magnet-cores and to easily adjust the commutating devices, l provide the lugs e on the yoke f 01:5. the machine, said in s being provided with circular holes d, which correspond with the diameter of the commutating cores a, and the said cores a are movable in these holes, and said lugs are preferably made scenes of an ample length in order to secure a sulficient contact-surface, and thereby reduce the vided with set-screws e for moving the com mutating-magnets in the desired position.

As this invention enables the commutatingmagnets to be constructed at a small cost, it has the further advantage that commutatormachines can be built on more rational lines than was possible hitherto, the chief consideration for the design being due in this as in other classes of electrical machinery to the heating alone.

in the above-described arrangement the axes of the magnet-cores radiate rectangu larly to the poleshoe face. As a more general disposition the cores can be arranged with their axes at any angle and in any suitable position relatively to the pole-shoe face. in this more general disposition the commutating-magnet cores'do not have a common plane.

in Fig. 3 of the drawings l have shown a modification oi the arrangement of the commutator-magnet cores a in that the said cores a are arranged obliquely, thereby enabling a longer core to be used and correspondingly a longer magnet-coil, thus reduc ing further. the weight of the magnet copper, this result being produced wit rout materially increasing the over-all dimensions of the ma chine, and it will be apparent that any suitable device for holding the cores a in position may be employed, and various other modifications with may he made without departing from the spirit of my invention or sacrificing its advantages.

in his. 5 of the drawings the armature is shown at 'o, the commutator at p, the brushes at q and (1 the line-wires at r and T and the various connections between the field-magnets m and the armature-magnets n are shown in series, and the armature 0 is also shown in l i l.

Having fully described my invention, what l/claim as new, and desire to secure by Letters Patent, is

1. A dynamo-electric machine, comprising a yoke, a plurality of pole-magnets arranged therein and around the armature of said electric machine, a lurality of commutating-magnets arrange in a different plane than said main magnets and the cores oi said commutating-magnets being arran ed radially in said yoke and being of a length greater than the cores of said main magnets, substantially as shown and described.

2. A ynamo-electric machine, comprising a yoke, a plurality of main pole-magnets ar ranged therein and around the armature of said electric machine, a plurality of commutating-magnets arranged in a diflerent plane than said main magnets, the cores oi' said commutatingmagnets being arranged radiin the scope of this invention common plane, plates or strips of conductive.

ally in said yoke and being of a length greater than the cores of said main magnets, and a conductive strip or plate connecting said main-magnet cores with said commutatingmagnet cores at the inner polesthereof, substantially as shown and described.

3. A dynamo-electric machine, comprisin a yoke, a plurality of main magnets arrange therein and in a common plane, a plurality of commutating-magnets arranged in said yoke and in a common plane parallel to but removed from said mainmagnet common plane and conductive strips or plates connecting the cores of said main magnets and said commutatingmagnets at their inner poles, substantially as shown and described.

4. A dynamo-electric machine, comprisin a yoke, a plurality of main-magnets in sai yoke and the cores of which are arranged radially therein and in a common plane, a plurality of commutating-magne'ts in said yoke and in a plane parallel to said main-magnet material connecting the cores of said main magnets with the cores of said commutatingmagnets, and means for adjusting the cores of said commutating-magnets radially, substantially as shown and described.

5. A dynamo-electric machine, comprising a yoke, a plurality of main magnets arranged in a common plane therein and the cores of said main magnets being provided with shoes at their-inner poles and being arranged radially in said yoke, a plurality of commutating-mag nets in said yoke and in a plane parallel to the plane of said main magnets, the cores of said commutating-magnets being also radially arranged in said yoke and being adjustable radiallytherein, substantiallyas shown and described.

6. A dynamo-electric machine, comprisin a yoke, a plurality of main magnets arranged in a common plane therein and the cores of said main magnets being provided with shoes at their inner poles and being arrangedradially in said yoke, a plurality of commutatingmagnets in said yoke and in a plane parallel to the plane of said main magnets, the cores of said commutating-magnets being also radially arranged in said yoke and being adjustable radially therein, shoes connected with the inner poles of said commutatingmagnet cores and projecting into the planeof said main-magnet cores and conductive strips or plates connecting said main-magnet shoes and said commutatin 'magnet shoes, substantially as shown and escribed,

7. In a dynamo-electric machine, a yoke, a plurality of main magnets radially arranged in a common plane therein, a plurality of commutating-magnets radially arranged in said yoke and in a common plane parallel to said first-named plane, the cores of said commutating'magnets being of a length greater a3, a l man the cores of said ma n magnets, and

devices for connecting the inner poles of said main magnets with the inner poles of said commutating-magnets, substantially as shown and described.

8. In a dynamo-electric machine, a yoke, a plurality of main magnets radially arranged 1n a common plane therein, a plurality of commutatin -magnets radially arranged in said yoke an in a common plane parallel to said first-named plane, the cores of said comthan the cores of said main magnets, and devices for connecting the inner poles of said main magnets with the inner poles of said commutating-magnets, comprising a shoe on each of said main-magnet-cores, an inwardlydirected shoe on each of said commutatingcores, and a strip or plate of conductive material connecting the adjacent pairs of said shoes, substantially. as shown and described.

9. In a dynamo-electric machine, a yoke, a plurality of main magnets radially arranged m a common plane therein, a plurality of commutating-magnets radially arranged in said yoke and in a common plane arallel to said first-named plane, the coresoi said commutating-magnets beingof a length greater than the cores of said main magnets, and devices for connecting the inner poles of said main magnets with the inner oles of said commutating-magnets, comprislng a shoe on each of said main-magnet cores, an inwardly- -directed shoe on each of said commutatingcores, and a strip or plate of conductive material connecting the adjacent pairs of said shoes, and. means for adjusting said commutating-magnet cores radially of said yoke, substantially as shown and described.

10. A dynamo-electric machine, comrising a yoke and within which is arrange the usual armature a luralit of main ma nets P Y s radially arranged in said yoke and the inner core-poles of which are in a common plane with said armature and slightly removed from the armature, a plurality of commutating-magnets in said yoke and arranged in a common plane parallel to the armature-plane, the cores of said commutating-magnets bein of a greater len th than the cores of sai main magnets t ereby allowing for a decrease in the length of the winding and an increase in the number of the windings thereon,

and electrical conductors connecting .the

main cores or shoes thereof with the commu I 75 mutating-magnets being of a length greater the number of windings thereon to produce the necessary commutating field, substantially as shown and described.

12. In a dynamo-electric machine, comprising a yoke, an armature and a plurality of main magnets, a plurality of commutatingmagnets arranged in a common plane parallel to the lane of said main magnets, the cores of said .comrnutating-magnets being of a length greater than the cores of said main magnets thereby decreasing the length of each Winding and increasing a number of windings thereon to produce the necessary eommutating field, and means for adjusting said oommutating-cores or the pole-shoes thereof, substantially as shown and described.

13. In a dynammelectric machine, comprising a yoke, an armature therein and a plurality of main magnets arranged in said ssones armature-plane, a plurality of commutatingmagnets the cores of which are longer than the cores of said main magnets, shoes on said main-magnet cores, shoes on said commutating-magnet cores, electrical conductors connecting said shoes with each other, and means for increasing or decreasing the air-gap between said commutating-magnet shoes and said armature, substantially as shown and described.

In testimony that I claim the foregoing as my invention 1 have signed my name, in presence of the subscribing Witnesses, this 15th day of May, 1905.

LUDVVIG TURDA.

Witnesses:

H. l). Jameson, F, S HANDS. 

